The invention relates to a resilient tire capable of supporting a vehicle load without the benefit of internal air pressure.
The pneumatic tire has been the solution of choice for vehicular mobility for over a century. The pneumatic tire obtains its mechanical attributes largely from the action of internal air pressure in the tire cavity, which provides correct rigidities to the belt and carcass components.
A difficulty with pneumatic tires is that good pressure maintenance is required to ensure adequate performance. When inflation pressure is lost entirely, a conventional pneumatic tire is capable of very limited, if any, use. Many tire constructions have been proposed to allow continued mobility of a vehicle after a complete loss of air pressure from the tire. One solution, the commercially available runflat tire, is a pneumatic tire having added sidewall reinforcements or fillers to permit the sidewalls to act in compression as load supporting members during limited deflated operation. This added reinforcement often results in the disadvantages of higher tire mass and reduced riding comfort. Other attempts to provide runflat capability utilize essentially annular reinforcing bands in the tire crown portion. In these solutions, the rigidity of the tread portion results partly from the inherent properties of the annular reinforcing band and partly from the reaction to inflation pressure. Still other solutions rely on secondary internal support structures attached to the wheel. These supports add mass to the mounted assembly and increase mounting difficulty or may require the use of multiple piece rims. All of these approaches are hybrids of an otherwise pneumatic tire structure and suffer from design compromises that are optimal for neither the inflated or deflated states.
In addition, these runflat solutions require the use of some means to monitor tire inflation pressure and to inform the vehicle operator if the inflation pressure is outside the recommended limits.
A tire designed to operate without the benefit of inflation pressure eliminates many of the problems and compromises associated with a pneumatic tire. There is only one operating condition, non-inflated. Neither pressure maintenance nor pressure monitoring is required. Structurally supported resilient tires such as solid tires or other elastomeric structures to date have not provided the levels of performance available in a conventional pneumatic tire. A structurally supported resilient tire solution that delivers pneumatic tire-like performance would be a welcome improvement.